write and exception error

[C Day]

XP Pro serpak3
filePro 5.0.14

Every two or three months, for three years I have been writing a text 
file created by Access to a filePro file with no problems.

Last night on about 20 records of over 8,000 during the posting process 
I got error:

the instruction at 00497afb referenced memory at 003df008 the memory 
could not be read from.

Or,

the instruction at 00480ee3 referenced memory at 64abe4a8 the memory 
could not be read from.

The memory location changed for each record but the instruction location 
was one of the two shown.


In the filePro file, I have six screens. When I stand on one of the 20 
errored records, on screen zero and change to screens 2, 3, 4, 5, or 6 
all is okay.  If I change to screen one, I get error:

exception error -1073741819 in process failed 0(0X00000000)
comspec=""
command="C:\backupmainfp\fp\rclerk


What is happening?

Charles Day